Method for producing hydroxy sulfolenes



Patented Sept. 9, 1952 METHOD FOR PRODUCING HYDRQXY SULFOLENES John E. Mahan, Bartlesville, Okla and Sig C.

Fauske Berger, Tex., Petroleum Company, a corporation of: Delaware- No Drawing Application October 21, 1949, Serial No. 122,858

12' Claims. 1

This invention relates to. a method for producing hydroxy sulfolenes. In a particular aspect this invention relates to the interaction of. ammonia with a 3-halo-4-hydroxy sulfolane to produce the corresponding 4-hydroxy-2-sulfolene as a product of the reaction.

It is an object of this invention to provide a method for producing hydroxy sulfolenes.

It is another object of this invention to provide a method for producing 4-hydroxy-2-sulfolenes by the interaction of ammonia with a 3-halo-4- hydroxy sulfolane.

It is a further object of. this invention to provide a method for producing 4-hydroxy-2-sulfolenes by the. interaction. of a primary or secondary amine with a.3-halo-4i-hyd roxy sulfolane.

Further and additionalobjjects of our, invention will be readily manifestfrom. our. disclosure hereinafter.

We have found that when. a '3'-halo-4-hydroxy sulfolane. is. reacted. withammonia or a primary or secondary. amine at. reaction. conditions to be specified hereinbelow, a. 4-hydroxy-2=sulfolene is. a product of the reaction. andfwe have found further. that the percentage yield of. 4.-hydroxy-2- sulfolene is dependent upon the reaction. conditions employed.

The 3-halo-4-hydroxy sulfolanesfor our process. may be obtained'from any suitable source or producedin any known manner. For example, a I

1,3-butadiene hydrocarbon and sulfur dioxide may be used as: starting materials,..the. butadiene having as a structural formula whereineach of R1,.Rz; R3 and. R4. represents hydrogen. or analkyl radicaL. such as methyl, ethyl, propyl, andthe. like, and wherein the sum of. the carbon atoms contained in. the 1,3j-butadiene molecule does. not exceed. ten. Throughout our disclosure, when. referring to a. I,3-butadiene,. we refer to. any 1.,3-butadiene hydrocarbon repre sentedby the abovestructural formula, and} when referring. to thespecificcompound. termed 1,3- butadiene, we refer to the hydrocarbon corresponding to: the abovestructural formula Wherein each of R1, R2, R2: and Bil-represents hydrogen. The sulfur dioxide andthewbutadiene are reacted using molar: ratios: of: sulfur: dioxide to the butadlenewithintherange; of 1.1:1 to: 3.21. and at an elevated'temperature and pressure. The temperassignors to Phillips 2 t ature may be within the range of 35 to. 150. G1, preferably 1.00 to 135 C., and the pressure maybe within the range. of to; 300 p, s.. i. Reaction periods of 0.25 to 6, preferably 1 to; 3', hoursare employed, and such polymerization inhibitorsias pyrogallol,v tert-butyl. catechol, and the like may be used... The. resulting products 3s-s'ulf'olene; conforms to the structural formula l y f i wherein R1, R2, R3 and R4 conform with the deflnition set forth above. TheB-sulfolene thus produced is then dissolved in water, and gaseous chlorine is introducediwith agitation at conditions of temperature and pressure such that the aqueous solution is in the liquid state until absorption of chlorine ceases. Upon completion of the reaction the resulting mixture is cooled, say, to a. temperature. of 10 to 25 C'. to crystallize andthur separate the desired reaction. product.- While chlorine. is preferred. for the halogenation. of' the aqueous solution. of: the 3-su1folene; as described above, any-halogen. selected from the. group con-- sisting of chlorine, iodine and bromine: may beemployed; The: principal product, a; 3-halo4ihydroxy" sulfolane, resulting from: halogenation reaction has thirstructuraliormula i--Q--QR4- l a Ra r o *0.

wherein. R1, R2,.R3. and Rliare'asdefined above. and. wherein X. represents a halogen selectedv from thegroup consisting of chlorine, iodine and bromine. This product. is a 3-halo-4,-hyd'roiiy sulfolane, and it. is used as a. starting material for our. novel reaction. The term. a 3.-h'alo- 4'- hydroxy sulfolane refers to any compound within the scope of. this structural formula, and. the term 3.-halo-4. hydroxy sulfolane refers to" the specific compound corresponding, to thisnstructural formula wherein each. of R1,. Rz Rg. and R4 represents hydrogen. Q a

The other starting. material is preferably am monia, but in. lieu of ammonia any primaryj or secondary amine may be used; The primaryor secondary amine should contain no more than twelve carbon atoms per molecule. The structural formula is representative of the ammonia and amines that may be used in our process. In this structural formula R and R represent hydrogen or alkyl, aryl, aralkyl, alkaryl and cycloalkyl radicals, and the sum of the carbon atoms in R and R does not exceed twelve. Typical examples of radicals that R and R may represent are methyl, ethyl, propyl, butyl, pentyl, phenyl, naphthyl, benzyl, phenyl ethyl, tolyl, xylyl, cyclopentyl and cyclohexyl. Also, R and R may represent members of a heterocyclic ring of which the nitrogen in the above structural formula is also a member. Typical examples of the heterocyclic compounds represented by the above structural formula are piperidine and its homologs and morpholine and its homologs. The above typical examples of R and R radicals and of the compounds represented by the structural formula are merely illustrative, but not exhaustive, of the radicals and compounds that may be used in our process.

The product resulting from the interaction of the 3-halo-4-hydroxy sulfolane with at least one of ammonia, primary amine and secondary amine, as defined above, is a 4-hydroxy-2-sulfolene, and the product may be represented by the structural formula wherein R1, R2, R3 and R4 conform with the definition set forth above. The term a l-hydroxy-2-sulfolene refers to any compound within the scope of this structural formula, and the term l-hydroxy-Z-sufolene refers to the specific compound wherein R1, R2, R3, R4 in the structural formula each represents hydrogen.

The yield of 4-hydroXy-2-sulfolenes obtained from our process is dependent upon the reaction conditions employed. During the reaction 3- amino-4-hydroxy sulfolanes are also produced, and we have found that high reaction temperatures and long reaction periods or contact times favor the production of the sulfolanes while low temperatures and short contact times favor the production of the sulfolenes.

The reaction temperature for our process is within the range of 5-0 to 200 0., and the contact time is within the range of one second to '72hours. To produce 4-hydroxy-2-su1folenes we prefer to operate with acontact time not above 24 [hours and 'with a temperature within the range of 35 to 100 C. As the reaction temperature and contact time approach the maximum limits of our specified ranges the yield of aminohydroxy sulfolane increases with a consequent decrease in the yield of hydroxy sulfolene. This fact will be shown in greater detail in our specific examples hereinbelow.

The reaction pressure employed is usually the autogenetic pressure of the reactants, but higher pressures may be employed. Pressures sufficient to maintain the reactants in a liquid state are preferred, and such pressures fall within the range of atmospheric to 1500 ps i.

The molar ratio of ammonia, primary or secondary amine to the 3-halo-4-hydroxy sulfolane is at least 2:1, preferably above 3:1. The upper limit, of this ratio is not critical, and ratios as high as 500:1 and higher may be used. During the reaction minor amounts of reaction by-prod- 'ucts resulting from the interaction of one or two molecules of the halo-hydroxy sulfolane with the amino-hydroxy sulfolane are produced, particularly when operating with relatively small amounts of ammonia or amine. In order to prevent the formation of excessive quantities of the by-products the molar ratio of reactants should be at least 2:1.

The above description of our process has been limited essentially to a method for producing hydroxy sulfolenes, but it is quite obvious that our process can also be employed to produce amino-hydroxy sulfolanes, more particularly 3- amino-4-hydroxy sulfolanes, having the general formula .the reaction products a temperature within the broad range of 50 to 200 C. and a contact time of one second to 72 hours are employed. However, to produce substantial yields of amino-hydroxy sulfolanes it is preferred that a, reaction temperature within the range of 30 to C. and a contact time of at least one hour be employed. At the reaction conditions we have disclosed the reaction effluent contains hydroxy sulfolenes and aminohydroxy sulfolanes, and. the percentage composition of each in the reaction efiiuent is dependent upon the reaction conditions employed.

The amino-hydroxy sulfolanes that are produced in accordance with our invention are soluble in water and acetoneand slightly soluble in acetonitrile, and these solvents may be employed to isolate the sulfolanes from other reaction products. Water has the disadvantage of causing a portion of the amino-hydroxy sulfolanes to hydrolyze, presumably to dihydroxysulfolane. The compound, 3-amino-4-hydroxy sulfolane, that we prepared is a white, crystalline solid and it was found to have a molecular weight of 151.18 and a melting point of 192-193 C.

Although our process may be effected in the absence of solvents, the reaction may be carried out in the presence of inert, normally liquid, organic solvents such as low molecular weight almatrsandsemera Typical i'examplesiofithesolr vent that may andidiethyl ether'a nditheirflow inoleculanweightdissolved in--"400-nrilliliters of liduid' ammonia-vat -33 C. and atmospheric pressures Aafter complete solutiony. oiwthe .suliolane. the zammonia was boiledoff as quickly as possible.

The reaction product was-extracted with-acetone tort'remove the-icmde4=hydroxy=2%sulfolene. r'lo'm the" ammonium chloride-formediir the reaction. The acetone solubler products? were separated from the insoluble ammonium chloride, and ,the acetone wasf strippedjfromithe; crude product. Analysis showed that th'e: negligible amountof chlorine aind nitrogen-r Determination of the hydroxylnumber on-a sample of the crude product showed that it contained 74 grams of 4-hydroxy-2-sulfolene. This represents a yield of 94.3 per cent of theory.

Further proof of the structure was efiected by redistillation of the crude product to obtain a material which boiled at 156 C. at about 0.2 'mm. Hg. It was analyzed for weight per cent carbon, hydrogen, and sulfur.

Found The product decolorized neutral potassium permanganate. The acetate derivative of 4-hydroxy-z-sulfolene was made, and its melting point of 114 C. was found to be in close agreement with the melting point of 1l2-113 C. reported for this compound in the literature. The product was found to be soluble in water, ethyl alcohol and acetone.

Example 11 Example III Another run was efi'ected in substantially the same manner as in Example I at the same temperature, but employing a contact time of 15 minutes instead of 1-0 minutes. The yield in this case was 92.4 per cent of theory of 4- ydroxy-2-sulfolene and 0.7 per cent of theory of 3-amino-4-hydroxy sulfolane.

Example IV Two further reactions between liquid ammonia and 3-chloro-4-hydroxy sulfolane were ples are illustrative of our This entirev operation was. carried outin fabout minutes:

product containedza" Calculated carried' iiout'r'in ian:autoclave: Theeobservedidutm ourj disclosure; hereinabove mo m9,

tions of our process within the scope of-our,

art, I 7 We. claim;

ventionwillbe apparent. to those skilledrin ithe I L. The process; which; comprises; interacting; a haioghydroxy. sulfolane 3 with a compound ,seja lected, from. ,the. group, consisting of ammonia, primary; amines. and... secondarmamines, rea covering at least one ofan hydroxy sulfole'neandl an amino-hydroxy sulfolane as'a product ofthe reaction.

2. The process for producing an hydroxy sulfolene which comprises interacting a halo-hydroxy sulfolane with a compound selected from the group consisting of ammonia, primary amines and secondary amines at a temperature and a contact time below that at which an aminohydroxy sulfolane is the sole organic product of the reaction.

3. The process for producing a 4-hydroxy-2- sulfolene which comprises interacting a 3-halo-4- hydroxy sulfolane with a compound selected from the group consisting of ammoniaprimary amines and secondary amines at a temperature and a contact time below that at which a 3-amino-4- hydroxy sulfolane is the sole organic product of the reaction.

4. The process which comprises reacting a 3- halo-4-hydroxy sulfolane having the structural formula wherein R1, R2, R3 and R4 each is selected from the group consisting of hydrogen and alkyl radicals, wherein the total number of carbon atoms in the molecule does not exceed ten and wherein X represents a halogen selected from the group consisting of chlorine, bromine and iodine, with a compound selected from the group consisting of ammonia, primary amines and secondary amines at a temperature not above 200 C and at a contact time not over 72 hours, and recovering a 4-hydroxy-2-sulfolene corresponding to said 3-halo-4-hydroxy sulfolane as a product of the reaction.

5. A process according to claim 4 wherein the reaction is efiected in liquid phase.

6. A process according to claim 4 wherein a temperature within the range of -50 to 200 C. is employed.

7. A process according to claim 4 wherein a contact time within the range of 1 second to 72 hours is employed.

8. A process according to claim 4 wherein the molar ratio of the compound selected from the group consistingof ammonia, primary amines and secondary amines to :sulfolane is at least 2:1. 9. A process according to claim 4 wherein the reaction is eifected in the presence of an inert;

liquid, organic solvent. v

' 10. The process which comprises reacting 3- chloro-4-hydroxy sulfolane with ammonia at a temperature. within. they range of -35 to 100 C. for a period of time not in excess of 24 hours at a pressure sufiicient to maintain a liquid phase reaction and employing a molar ratio of ammonia to sulfolane of at least 3:1, and recovering 4-hydroxy-2-sulfolene as a product of the reaction.

'11. The process for producing 'a 3-amino-4- hydroxy sulfolane which comprises interacting a.3-halo-4-hydroxy sulfolane with a compound selected from the group consisting of ammonia, primary amines and secondary amines at a tem- REFERENCES CITED The following references are of record in the 10 file of this. patent:

UNITED STATES PATENTS Number Name Date 2,430,821 Morris Nov. 11, 1947 15 2,435,071 Evans Jan. 27, 1948 2,465,912' 1 Morris Mar. 29, 1949- OTHER REFERENCES Weygand: Organic Preparations, DP. 207-208,

perature and a contact time above that at which 20 316, Interscience Publishers, N. Y., 1945.

a. 4-hydroxy sulfolene is the sole organic product of the reaction.

Whitmore: Organic Chemistry, pp. 75-76, Van Nostrand, N. Y., 1937. v 

1. THE PROCESS WHICH COMPRISES INTERACTING A HALO-HYDROXY SULFOLANE WITH A COMPOUND SELECTED FROM THE GROUP CONSISTING OF AMMONIA, PRIMARY AMINES AND SECONDARY AMINES AND RECOVERING AT LEAST ONE OF AN HYDROXY SULFOLENE AND AN AMINO-HYDROXY SULFOLANE AS A PRODUCT OF THE REACTION. 